The Primary Immunodeficiency Diseases Consortium (l) provides leadership and mentoring; facilitates collaborations; enhances coordination of research efforts; and solicits, reviews, and makes awards for pilot or small research projects; (2) maintains a primary immunodeficiency diseases registry, which provides data to the research community about the clinical characteristics and prevalence of these diseases; and (3) develops a repository of specimens from subjects with primary immunodeficiency diseases. The Consortium funds research proposals and continues to review new proposals 3 times each year.